These are either built because they are dependencies of other targets,
or not needed at all because they are used via extract_objects().
Mark them as "build_by_default: false"; if applicable, mark them
as "fa" so that -Wl,--whole-archive does not interact with the
linker script used for fuzzing.
(The "fa" hack is brittle; updating to Meson 1.1 would allow using
declare_dependency(objects: ...) instead).
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1044
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
4c545a05ab